Stress response of extensively reared young bulls being transported to growing-finishing farms under Spanish summer commercial conditions

To evaluate the effect of Spanish summer commercial journeys on the stress response of young bulls born and reared under extensive conditions, 2 replicates of a transport from an assembly centre to a growing-finishing farm were studied. Journeys lasted 27 h, involving a total of 62 young bulls. Variables under study included haematocrit, red blood cell count (RBC), total white blood cell count (WBC), differential WBC counts, serum haptoglobin (Hp), cortisol, glucose, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), total protein, and albumin at loading, at the end of an intermediate market stop, and at the unloading. Before the beginning of the journey elevated WBC and neutrophil counts, and high Hp values were detected, reflecting high stress levels probably as a consequence of previous procedures associated with the grouping at the assembly centre. Some stress was also detected at the end of the market stop, with cortisol increasing from 6.5 to 12.6 ± 2.0 ng/mL (P < 0.001), although a change in Hp concentration was not observed. Neither CPK and LDH activities, related to muscular tissue damage, nor haematocrit and RBC count, related to dehydration revealed a significant effect of this first stage of the journey on the physical stress of the young bulls. Subsequent 13 h transport to the growing-finishing farm induced an increase in Hp levels from 0.48 to 0.78 ± 0.16 mg/mL (P < 0.001), reflecting an onset of the acute stress response, although cortisol levels immediately after the unloading were similar to those found before loading at the market, suggesting that calves got accustomed to transport. At the end of the journey some dehydration and physical stress were also detected. Overall, our study provides new information to the discussion of the effect of temperatures during cattle transport. Although an improvement in pre-transport conditions is essential if the welfare of assembled and transported cattle is to be improved, the stress-related alteration of cattle physiology under Spanish summer commercial transport conditions is similar to that observed under colder conditions.     

Indicators of piglet survival in an outdoor farrowing system

Pre-weaning piglet mortality continues to be a major welfare and economic concern. In outdoor farrowing systems, there is a particular need to broaden breeding goals by incorporating selection for piglet survival to improve both productivity and welfare. This study aimed to identify behavioural and physiological survival indicators that are influential in outdoor systems and that could provide additional information for use when selecting for piglet survival. Data were collected from 511 piglets from Large White × Landrace × Duroc sows and Generalised Linear Mixed Models determined which indicators were most important for piglet survival in an outdoor system. With respect to prenatal mortality (surviving vs. stillborn piglets) high ponderal index (P < 0.001) or body mass index (P < 0.001) in conjunction with being born earlier in the farrowing birth order (P < 0.001) were the most important survival indicators. Birth weight (P < 0.001) and rectal temperature 1 h after birth (P = 0.032) were the most significant postnatal survival indicators. However survival indicators identified as important in indoor, conventional farrowing crates, such as landmark behaviours (latency to reach the udder, a teat and to suckle colostrum), were not influential in this system. These results highlight the importance of studying potential indicators of survival in alternative farrowing systems to the farrowing crate.     

Effects of management, environmental and temporal factors on mortality and feed consumption in integrated swine fattening farms

The purpose of this study was to assess the effects of management, environmental and temporal factors of farms and batches on mortality and feed consumed per market hog. Information of management, environmental and temporal factors from 158 all-in all-out finishing batches completed in 27 integrated fattening farms in Galicia (Spain) were collected from 1999 to 2002. Multilevel random effects models were used to determine the factors associated with the mortality and the average amount of feed provided per marketed hog. The level 1 unit was the finishing batch (batch level). At the level 2 the fattening farm where the batch of pigs was developed was introduced as random effects.A bad level of care provided by the farmer to the pigs increased the risk of mortality (P = 0.03). The mortality of the fattening batch was associated with the supplier sow farm (P < 0.01). The level of mortality of the batches of piglets entered the fattening farms both between January and April and October and December was higher than for batches incorporated from May to August (P < 0.01). The year when the piglets entered the farm was significantly associated with mortality (P < 0.01). The introduction of such variables in the multilevel model for mortality reduced the total unexplained variation by 41.06%. The proportion of the variation of the mortality attributable to the fattening farms was small (3.65%). The variability of mortality was higher when the placement of piglets was from September to December (P = 0.01).Higher consumption of feed was recorded when the feed was provided in a non-pellet form (P < 0.01). The introduction of piglets between September and December was associated with a higher consumption of feed (P < 0.01). The average final weight of the hogs was positively associated with the feed consumed per hog of the fattening batch (P < 0.01). The amount of feed provided per hog was statistically different among the years and these effects were modified by the level of mortality recorded in the batch and by the average weight of the marketed hogs. After introducing all the fixed effects in the multilevel model for feed provided per hog the unexplained variation at the farm and batch level was reduced by 47.72% and 85.35%, respectively. A considerable amount of variation of feed provided per hog resided at the fattening farm (32.50%). When the piglets were placed on September–December the variability of feed consumed was higher than in the other two periods of the year (P = 0.02). In conclusion, our study shows that specific factors of the batches are the main contributors to explain mortality. On the other hand, by improving permanent farm characteristics a substantial profit is expected in the long run as a result of lower feed costs.     

Multi‐level mixed models for evaluating factors affecting the mortality and weaning weight of piglets in large‐scale commercial farms in central China

This study investigated the factors affecting piglet mortality (square root of mortality, SQRM) and average weaning weight (AWW) in commercial farms in central China. Information on sow diets, management and climate from 2478 weaning batches completed in 16 pig farms was collected from 2009 to 2013. Multi‐level mixed models, which included batch level (level 1) and farm level (level 2), were used to analyze the factors associated with SQRM and AWW. The mean values of SQRM and AWW were 2.52% (SD = 0.96) and 7.31 (SD = 0.77), respectively. Lactation sow diets supplemented with oregano essential oils (OEOs) decreased the SQRM (P < 0.05) and increased the AWW of piglets (P < 0.01). The SQRM was lower in period 2 (June to September, hot) than in period 1 (February to May, warm) and period 3 (October to January, cold; P < 0.05 and 0.001, respectively). The AWW was lower in periods 2 and 3 than in period 1 (P < 0.01). In conclusion, supplying OEOs to lactation diets can increase the weaning weight and reduce the mortality of piglets. The sources of variations in SQRM and AWW are of greater concern in the warm season than in the hot season.     

Gut ecology, feed digestion and performance in weaned piglets fed liquid diets

Gut environment and microflora, digestibility, and performance were studied in weaned piglets in Central Vietnam fed a dry control diet (CO), a naturally fermented liquid diet (FE), and a liquid diet with inclusion of rice distiller's residue (RDR). Digesta samples were collected at the start (day 0) and at the end of experiment (day 42). Diet FE had a lower pH than diet RDR, contained more organic acids, had the lowest counts of E. coli and total coliforms (P < 0.05), and the highest counts of lactic acid bacteria (LAB) (P < 0.05). Piglets fed diets FE and RDR had lower pH (P < 0.05), and higher concentrations of organic acids in the stomach, ileum and mid-colon (P < 0.05) than piglets fed diet CO. Counts of LAB in stomach and ileum were higher in animals fed diets FE and RDR than CO (P < 0.05), while the number of E. coli and total coliforms along the gastrointestinal tract was reduced. The ileal digestibility of crude protein and organic matter was improved in piglets fed diet RDR (P < 0.05) compared with piglets fed diet CO. Piglets fed diet RDR had a higher weight gain (P < 0.05) and a better feed utilization (P < 0.05) than piglets fed the other diets. The present findings support the contention that fermented diets and/or fermented feedstuffs can be used for dietary manipulation to improve gut health and animal performance.     

Effects of composite antimicrobial peptide on growth performance and health in weaned piglets

This study was conducted to evaluate the effects of composite antimicrobial peptide (CAP) on growth performance and health status in weaned piglets. Over 28 days, 36 weaned piglets (body weight, 10.58 ± 0.99 kg) underwent three treatments: negative control (NC, basal diet), positive control (PC, basal diet + 20 mg/kg colistin sulphate + 50 mg/kg kitasamycin), and CAP treatment (CAP, basal diet with 400 mg/kg CAP). Average daily gain of piglets fed the CAP diet was greater (P < 0.05) than that of piglets fed the PC or NC diet during days 1–7, 8–14 and 15–21. Diarrhea rates of piglets fed the CAP or PC diet were lower (P < 0.05) than those of NC‐fed piglets during days 1–7. Apparent total tract digestibility for dry matter and crude ash in CAP‐fed piglets was greater (P < 0.05) than that of NC‐fed piglets. In the CAP group, Lactobacillus and Bifidobacterium counts were greater (P < 0.05) and Escherichia coli counts were lower (P < 0.05) than numbers for the NC group. Our results indicate that dietary CAP had beneficial effects on growth performance and health status in weaned piglets.     

Influence of sow dietary fatty acid composition on the behaviour of the piglets

Polyunsaturated fatty acids (PUFA) are essential for the development of the nervous system in animals, and increased concentration of n−3 PUFA in maternal diet improves the cognitive development of mammalian foetuses. In this study the effect of maternal diet fatty acid composition in pigs on the development of the central nervous system, monitored as behaviour of piglets, was investigated using three behavioural tests: recognition of the mother's faeces, back test, and hidden door test.Twenty-seven multiparous Yorkshire sows were split into four groups and fed diets with different content of fat and PUFA throughout pregnancy and lactation. LF (n = 6) was fed a standard diet, HFS (n = 4) a high fat and low PUFA diet, HFO (n = 7) a high n−6 PUFA diet, and HFL (n = 10) a high n−3 PUFA diet.Three behavioural tests were performed on 5–7 randomly chosen piglets per litter (n = 167). Recognition of the mother's faeces was tested in a maze two days after birth. Back test was performed twice (2–4 d and 4 w) and a hidden door test was performed at 4 w. In addition, the brain content of docosahexaenoic acid (22:6 n−3, DHA) of the newborn piglets was determined in treatment groups. Data from the tests were analysed with linear mixed models for each of the tests.Piglets from HFL treatment had significantly higher content of DHA (P < 0.001) and the ratio of n−6/n−3 PUFA was significantly lower in brain tissue (P < 0.001), compared to piglets from the other treatments. In parity 3, means for recognition for mother's faeces were for diets LF, HFS, HFO and HFL; 22.2, 37.0, 26.4 and 18.0%, respectively (P < 0.05), but no other significant effect of diet was found. Piglets in HFS treatment had the shortest latency to make escape attempts and HFO piglets the longest latency in the back test (P = 0.030). No significant effect of sow diet was found on piglet performance in the hidden door test, but intermediate piglets weighing 1410–1619 g had a lower probability of success in hidden door test than piglets weighing < 1410 g (P = 0.028), and ≥ 1875 g (P = 0.027), respectively.It was found that sow diet influenced the DHA content in the piglet brains, but there was no clear effect of sow diet on piglet behaviour. In order to draw any conclusions about possible enhancements of the behavioural development of the piglet more studies need to be performed.     

Duration of feeding linseed diet influences peroxisome proliferator-activated receptor γ and tumor necrosis factor gene expression, and muscle mass of growing–finishing barrows

The aim of the study was to investigate the effect of duration of feeding linseed (rich in n-3 PUFA) on peroxisome proliferator-activated receptor γ (PPARγ) and tumor necrosis factor (TNF-α) gene expression, and muscle mass of growing–finishing barrows. Two isoenergetic and isonitrogenous diets were formulated, and one of which was the basal diet and another one was the linseed diet including linseed at the level of 10%. Twenty-four Landrace × Yorkshire barrows weighing 35 ± 3.7 kg were randomly assigned to four treatments with six individuals per treatment. Pigs in treatment 1 (T1) fed the control diet throughout the experimental period, while pigs in T2, T3 and T4 fed the control diet except for 30, 60, and 90 d prior to slaughter when the linseed diet were fed. The experiment was conducted for 90 days. The longissimus muscle mass and each muscle mass in the hind leg were weighted. PPARγ and TNF-α mRNA expression levels in muscle, spleen and adipose tissue, and plasma concentrations of TNF-α data were measured and analyzed. The results showed that the longissimus muscle mass, quadriceps femoris muscle mass and semitendinosus muscle mass increased linearly (P < 0.01) as prolonged the time of feeding linseed diet. The expression of PPARγ in longissimus muscle and spleen increased (P < 0.01) linearly as prolonged the time of feeding linseed diet, while the expression of PPARγ in adipose tissue were not affected (P = 0.095). Duration of linseed addition linearly decreased (P < 0.01) TNF-α gene expression levels in the longissimus dorsi muscle, adipose and spleen, and serum concentration of TNF-α as well. The expression levels of PPARγ negatively correlated with the expression of TNF-α in muscle (R² = 0.70, P < 0.001) and spleen (R²R² = 0.77, P < 0.001) respectively. Likewise, PPARγ expression level in spleen (R²R² = 0.59, P < 0.01) or muscle (R²R² = 0.52, P < 0.05) negative correlated with serum TNF-α concentration, while there were significant quadratic relation between muscular PPARγ (R²R² = 0.80, P < 0.01) or muscular TNF-α (R²R² = 0.87, P < 0.01) expression and the longissimus dorsi muscle mass. These data suggested that duration of feeding linseed diet lead to a linear decrease of TNF-α gene expression, which may increase the muscle mass in growing–finishing barrows, at least in part, through a PPARγ-dependent mechanism.     

Effect of dietary supplementation of fish oil for lactating sows and weaned piglets on piglet Th polarization

The present study was designed to investigate the effect of dietary fish oil supplementation on piglet T helper cells (Th) polarization in relation to its impact on piglet serum interferon γ (IFN-γ) and interleukin 10 (IL-10) concentrations and splenic expression of Th1/Th2 characteristic genes. The diets of 18 gestating sows were supplemented with 7% lard (C) (n = 10) or 7% fish oil (T) (n = 8) from 10 d before parturition to weaning. At weaning, a split plot experiment was designed, 56 piglets, 28 each from sows fed with fish oil diet or lard diet, were divided into four groups of 7 replicates (one female and one castrated male per replicate) based on both sow diet during lactation and post-weaning piglet diet (C had 7% lard and T had 7% fish oil): CC, CT, TC, TT, and were fed the 7% fish oil or lard diet from day 35 to day 70. Serum concentrations of IFN-γ and IL-10, and Th1/Th2 related genes expression levels in spleen were measured and analyzed. The results showed that piglets fed with fish oil diet during post-weaning tended to have higher serum IFN-γ/IL-10 ratio (P = 0.09) than lard diet fed piglets. Lactation fish oil feeding increased splenic IL-12b, IL-12 receptor β2 (IL-12Rβ2), IL-2 and IFN-γ genes expression (P < 0.05 or P < 0.01) and post-weaning fish oil feeding increased splenic IL-12b (P = 0.06), IL-2 (P < 0.01) and IFN-γ (P = 0.08) mRNA expression than that in lard diet fed piglets at the end of this experiment. On the other hand, IL-4 gene expression (P = 0.01) in spleen was lower in weaned piglet from fish oil diet fed sows than that from lard diet fed sows. However, post-weaning piglets fed fish oil diet had higher splenic IL-4 (P = 0.06), IL-6 (P < 0.01) and IL-10 (P = 0.05) mRNA abundances than that fed with lard diet. These results indicated that dietary fish oil during lactation could increase Th1 polarization and accelerate immune maturation; while 7% fish oil in weaned piglets' diet was likely to increase Th2 cytokines expression.     

Maternal chitosan oligosaccharide intervention optimizes the production performance and health status of gilts and their offspring

Chitosan oligosaccharides (COS) are the hydrolyzed product of chitosan and have multifunctional health benefits. The objective of this study was to elucidate the effect of COS as a dietary supplement to gilts on their productivity and health and that of their litters. Gilts were randomly assigned to either a treatment (n = 30) or control group (n = 30). The treatment gilts were fed a standard dry sow ration supplemented with COS at 0.12 and 0.24 g/gilt per d during gestation and lactation, respectively, and the control group was fed the standard dry sow ration only. The body weight, reproductive performance, milk production and litter size for each gilt and body weight of corresponding litters were recorded. The serum immunoglobulins (IgA, IgG, IgM) and secretory immunoglobulin A (sIgA) concentrations of gilts and piglets and fecal sIgA concertation of gilts were measured by Enzyme-linked immunosorbent assay (ELISA). Our study showed that maternal COS supplementation 1) significantly increased gilt body weight in late pregnancy (P < 0.05), 2) significantly increased milk production of gilts at different stages (d 1, 3, 7 and 19) of lactation (P < 0.05), 3) significantly increased body weight gain of piglets at weaning (P < 0.05), 4) significantly increased the serum concentrations of IgM and sIgA in piglets, and sIgA in fecal sample of gilts (P < 0.05), and 5) tended to increase the pregnancy success rate (P > 0.05) in the treatment group compared to the control group. These results suggest that maternal COS intervention in gilts can improve gilt milk production, piglet pre-weaning growth and immunity parameters in both gilts and piglets.     

Serum acute phase proteins as biomarkers of pleuritis and cranio-ventral pulmonary consolidation in slaughter-aged pigs

The purpose of this study was to investigate the relationship between the existence of lung lesions in pigs at slaughter and the concentration of the serum acute phase proteins (APP), haptoglobin (Hp), pig-major acute protein (Pig-MAP) and C-reactive protein (CRP). A total of 24 pig farms were selected out of a larger farm database previously screened to study risk factors associated with pleuritis and cranio-ventral pulmonary consolidation (CVPC) lesions at slaughter-aged pigs in Spain. The farms were classified as “pleuritis negative (P−) or positive (P+)” and as “CVPC negative (M−) or positive (M+)” and divided into four groups according to a 2X2 factorial design (P−M−, P−M+, P+M−, P+M+). Also at slaughter, blood from 20 randomly selected pigs from each farm was collected. Obtained serum samples were used to measure acute phase proteins. All APP concentrations were significantly higher for M+ farms than for M− ones. However, only Hp and Pig-MAP showed significantly higher concentrations for P+ farms than for P− ones. Pig-MAP was the most sensitive biomarker since it was able to clearly discriminate between P−/P+ and M−/M+ groups (p < 0.001 in both cases). Hp was an excellent marker for pleuritis and good for CVPC lesions. CRP was able to discriminate for CVPC lesions but not for pleuritis. The present results indicate that Pig-MAP and, possibly Hp, may be used as potential markers to characterise and discriminate respiratory lesions in swine herds at slaughter.     

Maternal stress during late gestation has moderate but long-lasting effects on the immune system of the piglets

Events acting prenatally on developing foetuses are important determinants for disorders later in life. Prenatal stress (PNS) is one of these events. The purpose of this study was to determine the consequences of a repeated social stress applied during late gestation of the pregnant gilt on the immune system and hypothalamo-pituitary-adrenal (HPA) axis activity of the piglets from birth to two months of age. Pregnant gilts were submitted to repeated social stress which was induced by housing unfamiliar gilts in pairs modified twice a week during 4 weeks between days 77 and 105 of gestation (S group, n = 18). Control gilts were housed in stable pairs during the same period (C group, n = 18). Blood cortisol, haptoglobin and IgG levels, immune cell counts, mitogen-induced whole-blood proliferation and TNF-α production were evaluated in piglets at 4 days of age (D4), before and after weaning (D26 and 28) and before and after relocation to a new building (D60 and 62). We found that PNS did not affect growth rate of the progeny. It decreased the relative weight of adrenal glands on D4 (P < 0.05) but plasma cortisol levels were similar in both groups at all ages. IgG levels in colostrum and in the serum of piglets were not affected. PNS decreased the total numbers of white blood cells, lymphocytes and granulocytes from D26 to D60 (P < 0.05), the CD4⁺/CD8⁺ T cell ratio on D4 (P < 0.05), and LPS induced-TNF-α production on D60 (P < 0.05). PNS increased the ConA-induced lymphocyte proliferation on D4 and D60 and the PWM-induced proliferation on D60 (P < 0.05). Our results demonstrate that a repeated social stress applied to pregnant sows during late gestation can induce long-lasting effects on several parameters of the immune function of the offspring. These effects are not due to modifications of the HPA axis activity and may impair the abilities of the piglets to efficiently react against infections during the suckling period and around weaning.     

Effect of controlled alterations in maternal dietary retinol on foetal and neonatal retinol status and pregnancy outcome in pigs

The objective of this experiment was to examine the effects of feeding a vitamin A deficient diet (VAF) to pigs at different times on day 100 of foetal and days 0, 1 and 2 of neonatal development. Three treatments included a control (n = 12), VAF for 100 days before mating and during the first month of pregnancy (n = 13; VAF–control), and VAF during the oestrous cycle before mating and throughout pregnancy (n = 13; control–VAF). On day 100 of pregnancy, maternal liver and plasma retinol concentrations were reduced in both groups of gilts fed a vitamin A free diet compared to controls (P < 0.001 and P < 0.01, respectively). Day 100 foetal liver retinol concentrations were not affected by dietary treatment, whereas foetal plasma concentrations were higher in foetuses carried by gilts fed the VAF–control diet (P < 0.05). Piglets born to mothers fed the control–VAF, but not the VAF–control diet had consistently lower hepatic and plasma liver retinol concentrations (P < 0.05). Moderate reductions in maternal vitamin A at either stage of pregnancy did not affect pregnancy rate, litter size, progesterone secretion or the allometric relationships between foetal or neonatal organ and total body size. Reduced vitamin A during conception and early pregnancy, but not during later pregnancy, was associated with increased within-litter uniformity in birth weight (P < 0.05) and a tendency for fewer low birth weight piglets, but this needs to be confirmed in a greater number of sows. The mechanism underlying this effect is not known, but appears to not involve an alteration in progesterone production.     

Characteristic of duodenal myoelectric activity in relation to food in piglets during the 3rd and 4th week of life

The relationship between duodenal myoelectric activity and liquid food intake was investigated in eight conscious piglets with bipolar electrodes implanted on the wall of the duodenum. Piglets were fed with commercial milk formula and the effects of volume and feed dry matter intake on duodenal myoelectric activity were measured by means of an analog–digital recording system.The cyclic pattern of duodenal myoelectric activity, i.e. the migrating myoelectric complex (MMC), was preserved when piglets received small meals at regular intervals. The duration of the whole MMC cycle, as well as the duration of phase II of the MMC, were only weakly correlated (r = 0.2, P < 0.05 for both parameters, respectively) to the amount of ingested food. However, the increase of the amount of feed dry matter intake of a meal from 2.1 to 4.5 g kg^− 1 of live body mass (LBM) as well as an increase of volume of a meal from 13 to 26 ml kg^− 1 LBM significantly increased the duration of the MMC cycles (P < 0.05) due to the elongation of phase II of the MMC (P < 0.05).The present study shows that in piglets fed with a liquid diet the upper gut motility response to food is similar to that previously observed in adult animals.     

Influence of dietary fat source on sow and litter performance,colostrum and milk fatty acid profile in late gestation and lactation

The objective of this study was to investigate the effects of dietary supplementation with various fat sources (3.8–3.9% of diet) during late pregnancy and lactation on the reproductive performance, fatty acids profile in colostrum, milk and serum of sow progeny. A total of 80 multiparous sows were randomly fed a control (adding no oil), palm oil (PO), fish oil (FO) or soybean oil (SO) supplemented diet from 90 days of pregnancy to weaning. Supplementation of FO increased litter size of weak piglets, compared with the control‐fed sows (P < 0.05). Dietary FO and SO supplementation, enhanced the weaning survival rate, litter weaning weight, litter weight gain and fat content in milk (P < 0.05). The highest immunoglobulin (Ig)G and IgM levels in colostrum and milk were observed in the FO group (P < 0.05). Meanwhile, the highest concentration of C22:5 (n‐3) and C22:6 (n‐3) in colostrum, milk and piglet serum was observed in the FO group (P < 0.05). Taken together, dietary inclusion of FO or SO improved growth performance of nursing piglets by increasing milk fat output, and FO consumption by sows might benefit the piglets via increasing n‐3 polyunsaturated fatty acid availability and immunoglobulins (IgG and IgM) secretion.     

Effect of δ-aminolevulinic acid on growth performance, nutrient digestibility, blood parameters and the immune response of weanling pigs challenged with Escherichia coli lipopolysaccharide

This study investigated the effects of dietary δ-aminolevulinic acid (ALA) on growth performance, nutrient digestibility, blood parameters and whether ALA improved the immune response of weanling pigs challenged with Escherichia coli lipopolysaccharide (LPS). Eighty pigs (body weight = 7.21 ± 0.51 kg) were allotted to four dietary treatments, with four pens per treatment and five pigs per pen. Basal diets were supplemented with 0, 5, 10, and 15 mg/kg ALA (as-fed basis) and fed for 35 days. At the end of the feeding period, 10 pigs were selected from both the 0- and 10-mg/kg ALA treatment groups; five were injected i.p. with LPS (50 μg/kg BW) and the other five pigs with an equivalent amount of sterile saline, resulting a 2 × 2 factorial arrangement. Blood sample and rectal temperature data were collected at 0, 2, 4 and 12 h after challenge. Growth performance was not affected by dietary treatments over the total experimental period. However, dry matter (DM) and nitrogen (N) digestibility was improved in the 15-mg/kg ALA treatment group at day 35 (P < 0.05). Serum hemoglobin (Hb) and iron levels were also increased, with the 10-mg/kg ALA treatment showing the highest concentration (P < 0.05). On day 35, red (RBC) and white blood cell (WBC) counts were elevated, with the 5- and 10-mg/kg ALA treatments having the highest counts (P < 0.05). During challenge, LPS injection elevated rectal temperature at 2 and 4 h postchallenge (P < 0.05). Plasma cortisol concentration was also increased by LPS injection at 2 and 4 h postchallenge and an ALA-alleviating effect was evident at 2 h postchallenge (P < 0.01). Concentration of plasma insulin-like growth factor-I (IGF-I) was increased in the ALA-supplemented treatments at 2 h postchallenge (P < 0.05). LPS injection increased plasma tumor necrosis factor-α (TNF-α) concentrations at 2, 4 and 12 h (P < 0.01), while an ALA-alleviating effect was observed at 2 and 4 h postchallenge (P < 0.05 and P < 0.10, respectively). Challenge with LPS decreased WBC counts at 2 and 4 h postchallenge (P < 0.01). At 12 h postchallenge, RBC, WBC and lymphocyte counts were affected by LPS challenge, while an ALA effect was only observed on WBC count (P < 0.05). In conclusion, dietary supplementation of ALA in weanling pigs can improve DM and N digestibilities, and iron status and have a beneficial effect on the immune response during inflammatory challenge.     

Calcium homeostasis, acid–base balance, and health status in periparturient Holstein cows fed diets with low cation–anion difference

Forty multiparous Holstein dry cows on d 21 prepartum were randomly allocated to four blocks of 10 cows to examine the effects of reducing the dietary cation–anion difference (DCAD) on calcium homeostasis, acid–base balance, health status, and subsequent lactation performance. The reduced DCADs (Na + K − Cl − S, mEq/kg DM) of + 150,+ 50, − 50, and − 150 were obtained by addition of anionic salts. Reducing DCAD resulted in mild metabolic acidosis as indicated by the sharp decline in urinary pH, and minor reductions in blood pH and HCO₃⁻ concentration. Greater plasma calcium concentration was observed in cows fed diets of − 50 and − 150 DCAD (P < 0.05) than those on + 50 and + 150 DCAD diets. The nadir of plasma calcium level on the day of calving was lower (P < 0.05) than the highest level on d 14 prepartum (8.33 vs. 9.30 mg/dL). Composite colostrum calcium concentration was decreased (P < 0.05) with time on d 1 relative to d 2 postpartum (0.212 vs. 0.174%), and feeding of diet − 150 DCAD induced higher (P < 0.05) composite colostrum calcium content than other three DCAD diets. No case of milk fever occurred for any diets, but feeding the two negative DCAD diets reduced (P < 0.05) retained placenta incidence compared with diet of + 150 DCAD. Dry matter intake, milk yield and compositions of fat, protein, and lactose were non-significantly affected (P > 0.05) by dietary treatments. In conclusion, urinary pH is an effective indicator of extracellular fluid acid–base balance, and feeding negative DCAD in late gestation period is beneficial for dairy cows in blood calcium homeostasis and improvement of health status.     

Factors affecting the mortality of weaned piglets during commercial transport between farms

Factors affecting the number of weaned piglets found dead after commercial transport between farms were studied by means of multilevel Poisson regression. Information relating to 58,682 piglets during 109 journeys in different EU countries was collected at the end of each journey by means of questionnaires. Overall, 0.07 per cent of all the transported piglets were found dead on arrival, and deaths of piglets were recorded in 13.8 per cent of journeys. The final regression model, which was calculated using the complete records from 105 journeys, included the total duration of the journey, the mean outside temperature during the journey, whether the piglets were fasted before transport, whether drinking water was provided, the type of ventilation in the vehicle and the interaction between journey duration and the mean outside temperature. The duration of the journey and the mean outside temperature showed a significant interaction effect, with a gradual increase in the predicted number of dead piglets with increasing journey duration as the outside temperature increased. Providing the piglets with drinking water and having mechanically assisted ventilation (fans) in the vehicle during the journey significantly reduced the number of deaths, as did fasting the piglets before transport.     

Dietary supplementation with Acanthopanax senticosus extract enhances gut health in weanling piglets

The present study was conducted to investigate the effects of Acanthopanax senticosus extract (ASE) as a dietary additive on gut health in weanling piglets by examining diarrhea frequency, intestinal microbiota and morphology. A total of 96 Duroc× (Landrace × Yorkshire) piglets weaned at 21 days of age with an average initial body weight (BW) of 5.6 ± 0.4 kg were randomly assigned to 3 treatment groups with 4 duplicates of 8 piglets each. The piglets were fed basal diet to which had been added 0 or 1 g/kg of ASE, or 0.7 g/kg antibiotics, respectively. Fecal consistence was monitored twice daily and the frequency of diarrhea was calculated. On day 21 after the initiation of supplementation, 8 piglets were randomly selected from each treatment group (2 piglets per pen) and slaughtered. The jejunum, ileum, colon and cecum were then excised and fixed in 10% neutral formalin solution to determine villus height and crypt depth, after their contents were collected to determine microbiota. The results showed that dietary supplementation with ASE increased (P < 0.05) the density of bacterial populations that co-migrated with Lactobacillus amylovorus, Lactobacillus salivarius, Bacillus subtilis, and Clostridium lituseburens, but decreased (P < 0.05) those co-migrating with Staphylococcus aureus, Salmonella typhimurium, Ruminococcus forques, and E. coli O157:H7 in the PCR-DGGE profiling analysis when compared with the control group. The villus height of the duodenum, jejunum and ileum increased (P < 0.05) by 14.8, 13.7 and 10.0%, while the crypt depth decreased (P < 0.05) by 17.9, 9.1 and 12.1%, respectively, in response to dietary ASE supplementation. Additionally dietary supplementation with ASE or an antibiotic decreased (P < 0.05) the frequency of diarrhea by 55.6 and 52.2%, respectively, compared with the control group. In conclusion, these findings suggest that dietary supplementation with ASE could regulate the microbiota composition and maintain a normal morphology of gut mucosa in weanling piglets, thereby decreasing diarrhea that resulted from weaning stress.